Standing in the polling booth this Saturday, Australians will do more than vote.

Key points:

Experts say voters don't understand that their votes directly lead to funding for political parties

The system is designed to reduce reliance on donations but it's not working

A donation crackdown has been recommended

They will channel tens of millions of dollars to the country's political operatives — to fund advertising to those same voters.

Whether an Australian backs the party of their parents, follows the first how-to-vote card they come across or votes like a donkey, the result is almost always the same: $2.76 will go to the party or candidate alongside the box marked "1" to meet their advertising costs.

That means a vote for the same party in both houses returns about $5.50 per person.

The only exceptions are votes going to a candidate with less than 4 per cent of the vote, and informal votes.

Joo-Cheong Tham, a professor in democracy from Melbourne Law School, believes most voters are oblivious to the scheme.

"I don't think the system is difficult to understand, but I suspect most people don't actually appreciate there's public funding of political parties and candidates," he said.

A good thing, to an extent

The system of public funding was set up in the 1980s by the Hawke government to reduce the risk of corruption associated with donations, Professor Tham explains.

"The idea behind it was that public funding — because the parties and candidates receive public funding, they could be less reliant upon private funding," he said.

Funding since it was introduced is more than $400 million.

It's grown steadily since payments for Upper and Lower House votes were aligned in mid-1990s. The amount per vote rises with the rate of inflation.

The Grattan Institute's Kate Griffiths said some level of taxpayer funding was needed to cover politicians' salaries, staff and expenses, and the funding of advertising is an extension of that principle.

"That's a recognition that the role they play is one of representing the public if they're to be elected," she said.

"They're prompted by concerns about how much money has gone to Pauline Hanson's One Nation Party," Professor Tham said.

"Public funding payments actually exceeded the amount of electoral expenditure the party incurred."

The Parliamentary Library found One Nation, the Nick Xenophon Team, Derryn Hinch's Justice Party and Bullet Train for Australia would have received less funding in 2016 if the new funding cap had applied at the time.

Parties will have to lodge evidence of electoral expenditure, and the ABC understands the Australian Electoral Commission is wary of potential disputes in applying the new rules.

A new approach

Both Professor Tham and the Grattan Institute have recommended tweaks to Australia's public funding and election advertising systems.

"If you were to cap the amount that they can spend during an election campaign, it limits the arms race for more and more donations and reduces the influence of any one donor in the system," Ms Griffiths said.

Professor Tham would like to see public funds used to encourage democratic participation.

"I think having measures in place that ensure that rather than having big money and big amounts coming to our political parties, we have big money in small sums," he said.

That could mean a system of funding tied to the number of members of a political party, as well as matched taxpayer funding for small donations.